- Indexed Arrays 5:13
- Adding Array Elements 5:08
- List Quiz 5 questions
- Removing Array Elements 4:50
- Editing Array Elements 1:36
- Modifying Arrays 3 objectives
- Associative Arrays 3:48
- Associative Quiz 5 questions
- Mixing Data Types in Arrays 6:07
- Multidimensional Arrays 6:14
- Multidimensional Arrays 3 objectives
- Sorting Arrays 6:16
- Mixing and Sorting 5 questions
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Multidimensional Arrays
6:14Multidimensional arrays allow me to create an nested array of information for each item in my list. In this video we'll take a look at the format for creating multidimensional arrays.
We've seen how arrays can be
used to group information and
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store multiple pieces of
information in one variable.
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Multi-dimensional arrays take
this concept to the next level.
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Our first array was a list of things
to learn, each item was stored
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as a simple string but what if I wanted to
track more information about these items.
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Maybe, I'd like to add
a priority to each item, so,
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that I know which item I
need to complete first.
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I might also want to set a due date for
an item or
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maybe I want to keep my items in a list
and just mark the item as complete.
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Multi-dimensional arrays
allow me to create
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a nested array of information for
each item in my list.
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Let's take a look at the format for
creating multi-dimensional arrays.
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Let's add a new file named todo.php
Adding the opening and closing PHP tags.
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To start, I'm going to create a single
task as an associative array of details.
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Task one equals an array.
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The first element,
title double arrow Laundry.
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The second element, priority.
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Double arrow 2.
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Due double arrow an empty string and
complete.
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Will equal the Boolean true.
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When writing an array on
multiple lines just like we did,
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the common practice is to end with a comma
making it easy to add the next element.
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Let's var_dump task1.
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And then run our script.
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Okay, so we have our first
task as an associative array.
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Let's add a second task.
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This title will equal
clean out refrigerator.
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We'll set the priority to 3.
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And this will be due on 7/30,
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2016 The complete status.
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Will be false.
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Now let's add both these
tasks as elements to a list.
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Task one and task two.
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Now let’s var dump our list.
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Pull the console way up and
run the script.
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As you can see from the var dump,
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the first array list has two elements,
starting with a zero index key.
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The first element is
an array of four items.
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Each of these items has
a specific string key
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describing which detail the item contains.
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Let's comment out this var dump.
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If I want to access
the title of my first task.
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I use echo list.
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The key of zero for my first task
followed by the title for my inner array.
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Now when I run my script I see
the title for my first task Laundry.
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Let's take a look at a few
other formatting options.
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Since I know that I'm going to
add these tasks to my task list.
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I can remove the extra variables and
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add these tasks to my list
right from the start.
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I just list add an element
that's an array list
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add my second element
that is also an array.
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I no longer need this line.
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As of PHP five four,
you can also use the short array
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syntax which replaces array and
parentheses with the square brackets.
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Open and close.
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Open and close,
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you'll often see this short array syntax used,
when creating multi-dimensional arrays,
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or even associative arrays,
whichever syntax you use.
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Spacing is key for
helping you make sure that you open and
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close all the symbols properly.
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Let's use this var dump and
run the script again.
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Pulling my console all the way up, and
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we see that the structure of
the array hasn't changed at all.
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I could also specify the keys for
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my first array by adding a key
to the first square brackets.
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Task one.
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Task two.
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There's not really a good
reason to specify a key here so
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I'm going to change that first
level back to a zero index array.
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Multi-dimensional
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arrays can be a complicated
concept to grasp.
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I encourage you to re-watch this video and
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also experiment with some
multi-dimensional arrays of your own.
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Also make sure you check out
the teacher's notes for more resources.
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Before we conclude this section on arrays
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we'll take a look at one more aspect
that makes arrays a powerful tool.
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The ability to sort.
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